A commission appointed by New York Governor Andrew Cuomo has been studying barriers and “natural protective systems,” and is expected to issue its findings as early as Monday.

Architects and planners — as well as Mayor Michael Bloomberg — have raised numerous concerns about building a wall around the city, like those in the Thames River or in the Netherlands. It would be costly, around $20 billion, and would take years to pass environmental reviews. Plus, a barrier stretching from Staten Island to Breezy Point, Queens, could push the storm surge onto areas immediately adjacent, like New Jersey and Long Island, and make flooding worse there.

(Landscape architect’s Kate Orff’s sketch showing a chain of man-made islands between Coney Island and New Jersey’s Sandy Hook. Her plan also calls for “soft” edge measures like dune replenishment in the Rockaways./Scape Studio.)

But she says the islands, while they would absorb some of a storm surge, would not do the trick alone.

“You can’t just have a piece of land and an island and assume that the land will be protected,” she said in an interview. “The water would just go around that barrier.”

So Orff says traditional iron sea gates would still be needed. They would connect the islands to make sure a storm surge did not reach Upper New York Bay. (They would normally be retracted in order to let ships and ferries pass.) Dunes and salt marshes also would be replenished along Long Island and Jamaica Bay to provide protection for those areas.

(The islands would build upon a series of islands and shoals that have gradually eroded or dredged over the past few hundred years./Regional Plan Association)

Susannah Drake, principal of DLANDSTUDIO, says the miniature islands would absorb the force of a storm surge better than a steel hurricane barrier.

(A design for the Museum of Modern Art’s 2010 Rising Currents exhibit, which called for a series of man-made islands south of Manhattan./Architecture Research Office/DLANDSTUDIO)

“Instead of the force hitting back like a fist hitting a wall, the force hits a sponge,” she said. “The grasses will flex and will break down the force.”

In addition, the design proposes remaking the Lower Manhattan with areas that would collect excess flood waters and other parts that absorb it. Drake said the design had been tested to accommodate the volume of water expected to inundate Manhattan in a 100-year-flood.

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Matthew Schuerman joined WNYC in December 2007 as the transportation and economic development reporter. He covered repeated financial crises at the MTA, the most severe transit cuts in decades, as well as the impact of the recession on the Atlantic Yards project in Brooklyn and the World Trade Center redevelopment in Lower Manhattan. Since 2010, Schuerman has been an editor in the WNYC newsroom. In addition, he has recently reported a number of Sandy-related stories.

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